...Metamorphic Rocks University Of Phoenix By: Laurea Pruitt August 29, 2010 Where do metamorphic rocks originate? Metamorphic rock is produced from pre-existing rock that is altered, but not melted by heat and pressure deep below the earth's surface. Common metamorphic rocks include marble, which forms from limestone, and slate from shale or mudstone. If the pressure and heat increase to the point where the rock melts, magma forms to produce new igneous rock. They originate from non-metamorphic rocks which get changed in some way; for example through pressure and temperature. Typically rocks that form near surface undergo progressive burial or seduction, exposing rocks to higher temperature and/or pressure conditions than they saw at formation. The changes in pressure and temperature cause the minerals to deform and recrystallize, and even involves changes in bulk chemistry addition or removal of chemical constituents like water and carbon dioxide. When you find metamorphic rocks at the surface of the earth, that means that either a lot of rock has eroded, exposing the rocks that were once much deeper in the crust, or there has been some really significant fault movement that has brought the rocks from deep in the crust toward the surface. Metamorphic rocks are formed from Igneous or sedimentary or both type of rocks due to excessive heat. The rocks first change their shape and size and then due to pressure, they become metamorphic rocks, Most metamorphic rock classification...
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...Metamorphic rocks We will be talking about Metamorphic rocks. How they were made. How they beacom rocks. Also, why there there here in life and how they became on this are. Also, where they are placed around the globe. Making over 12% of the Earth’s landmass. Metamorphic rocks are formed through the metamorphosis, or transformation. metamorphosis can be achieved through either extreme pressure or heat. Some examples of foliated metamorphic rocks include slate, gneiss and schist. Some examples of non-foliated metamorphic rock are quartzite and marble. Non-foliated means it's not foliated. Metamorphic rocks formed through extreme pressure are known as foliated metamorphic rocks. Nonfoliated metamorphic rocks and are a result of the re-crystallization of the protolith. Which is the original rock before it was metamorphosed. Metamorphic rock are formed by extreme...
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...Earthquakes and fault lines Scientists and geologists have a pretty good understanding of how the plates move and how this is related to earthquake activity. There are four different types of plate boundaries. First we have Divergent boundaries, where new crust is generated as the plates pull away from each other. Second we have Convergent boundaries and this is where the crust is destroyed as one plate is forced under another. Third we have the transform boundaries and this is where the crust is not created or destroyed as the plates slide horizontally past the other. Last we have Plate boundary zones where broad belts in which boundaries are not well defined and plate interactions are not clearly understood. The best known divergent boundaries is the mid-Atlantic Ridge, it is a submerged mountain range, which extends from the Arctic Ocean down South of Africa. This mountain range has been spreading apart for millions of years, which allows new magma to surface thus increasing the size of the mountains 2.5 centimeters each year. The two plates involved here are the American and the Eurasian plates and they are separating Iceland. The convergent boundaries are where the crust is being destroyed at about the same rate as it is being replaced in other areas of the world. These boundaries are long and deep trenches in the ocean and it are created by one plate being forced under another. These areas include the ring of fire which is a geographic region that has volcanoes that are...
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...Cauvery shear zone itself contains the older rocks like 3.0 Ga Sittampundi anorthosite and the younger Tiruchengodu granite of 660 Ma old (Bhaskar Rao et al., 1996). SGT is characterized by the presence of few major shear zones and deep crustal faults and is bounded by shear zone/fault immediately bordering the Kodaikanal hill ranges (Janardhan, 1999). Prominent among them are Moyar Bhavani, Palghat-Cauvery and Achankovil shear zones. These shear zones represent major terrain boundaries in south India. The major shear zones, E-W trending Palghat-Cauvery in the north and NW-SE trending Achankovil in the south, divide the SGT into (a) Northern Block (b) Madurai Block and (c) Trivandrum Block. The Northern Block composed of orthopyroxene bearing granulites and hornblende biotite gneiss and syenite and carbonatite intrusive bodies (750 Ma) that occur along Salem-Attur and Mettur shear zones. The triangular shaped land mass bounded by Moyar shear zone in the north and Bhavani shear zone in the south is known as Nilgiri block. Nilgiri block represents the deepest level of exposure (9-10 kb; palaeo-depth of ~ 35 km) of granulite grade lower crust in south India. The crustal section is essentially composed of garnetiferous hypersthene bearing tonalitic granulites with smaller amount of kyanite-bearing gneisses, quartzites and banded magnetite quartzites. Its deeper northern part is encroached by intermediate and basic magmatic rocks presently represented by non-garnetiferous...
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...multiple choice questions that follow the essay/shot answer questions, as a doc, docx or pdf file. Good Luck! 1. Differentiate between relative and absolute dating. List, define and discuss the principles used to define relative age. Discuss isotopic dating: what atomic particles are involved, what are some common isotopes that are used, and what are some uses of isotopic dating? Be sure to explain the calculation of the age of a rock. Relative dating is telling us the age of something compared to that of the substances around it, more plainly stated the sequence of events. Absolute dating tells how old something is, an amount of time can be associated with an object unlike in relative dating. There are four stratigraphy principles used to determine geologic history of a locality or a region: 1) original horizontally, 2) superposition, 3) lateral continuity, and 4) cross-cutting relationships. Original horizontally states that beds of sediment (sedimentary strata) deposited in water forms as horizontal or nearly horizontal layers. If rocks that are at inclined/folded have moved from their original position. The principal of superposition says that within deposition of sediment the oldest layer is at the...
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...Introduction: Every aspect of our surroundings, everything we witnessed at the two sites that we visited and everything geologically related can be tied together with a few simple concepts. A central component of those simple concepts is known as the Wilson Cycle. The Wilson Cycle has a massive impact on not only the two sites that we visited, but literally everywhere around the world. By understanding the principles of the Wilson Cycle, we are able to unearth details about a location such as what geologic era it belongs to, what type of plate boundary it is, as well as what type of tectonic activity that was required to allow it to form. In essence, everything relates back to the Wilson Cycle, as evidenced in the following pages. Geologic Background: PALEOZOIC: The Paleozoic era was is the earliest of the three geologic eras and spans from about 542 to 251 million years ago. Numerous events that significantly impacted the overall structure of the earth took place during this time period. The Paleozoic Era is divided into six different subcategories which include: the Cambrian, Ordovician, Silurian, Devonian, Carboniferous, and Permian. Early in the Paleozoic the continents were far apart but moving tectonic plates caused continents to move together into one large continent called Pangaea. Some of the significant geologic events that occurred during the Paleozoic era includes the evolution of a large number of animals, some of which are distant ancestors to modern organisms...
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...general name for a group of magnesium rich hydrous sheet silicates possessing similar structure and chemical composition. Many green rocks owe their color to chlorite and chlorite owes its name to its green color. The Greek word choros, meaning “green,” is the origin of chlorite’s name. Consisting of negatively charged mica-like (2:1) layers regularly alternating with positively charged brucite-like (octahedral) sheets, the basic structure of chlorites allows for various compositions(Grim,1962). Members are differentiated by substitutions within the octahedral layer and the tetrahedral or octahedral positions of the mica-like layer. The arrangement of hydroxide and 2:1 sheets stacked in the z-direction defines the polytype of chlorite. There are theoretically six possible layer interlayer assemblages in either semi-random or regular "one-layer" polytypes. Of these six polytypes, four have been observed in nature (Partice De Caritat ect. 1993): clinochlore (Mg,Fe2+)5Al(AlSi3O10)(OH)8, chamosite (Fe2+,Mg)5Al(AlSi3O10)(OH)8, nimite (Ni,Mg,Al)6((Si,Al)4O10)(OH)8, and pennanite Mn52+Al(AlSi3O10)(OH)8. Provenance Chlorite is widespread throughout the world, often found in low- to medium-grade regional metamorphic rocks and as a secondary mineral to mafic silicates in igneous, metamorphic, and sedimentary rocks. It is an occasional constituent of igneous rocks, in most cases probably forming secondarily by deuteric or hydrothermal alteration of primary ferromagnesian minerals, such as mica...
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...Abstract Central Texas contains Precambrian rocks, which were exposed due to the Llano uplift. This paper looks further into the Devil’s Waterhole of Ink’s Lake to get a better understanding of the area. First the geology of the Llano uplift is studied to get a better understanding of how the rocks in the area were formed. The rocks in the area, which consists of Valley Springs Gneiss and Town Mountain Granite, are studied even further to see the composition of each and how each was formed. The Valley Spring Gneiss is split into amphibolite, biotite gneiss, quartz-feldspar gneiss, and quartzite. Each of the five different rock samples were observed and studied in the area to give us a better understanding of their compositions, how they were formed, and what their protoliths are. The Devil’s Waterhole of Ink’s lake is the area of focus in studying Precambrian rock. Throughout the Ink’s Lake region we will take focus on the Precambrian metamorphic rock that was exposed due to the Llano uplift. The Llano uplift contains some of the oldest rocks in North America and is exposed in Ink’s Lake, Texas. This is exposed due to the oceanic-continent collision, which drove the Llano uplift upward. After the weathering away of the younger rock on top, the currently exposed metamorphic rock is more easily observed. Following the Llano uplift exposure, there was an intrusion of the Town Mountain Granite, which we will also look further into. We also observe the areas reactions such as...
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...Every Rock Tells A Story They say every rock tells a story, but I believe there is much more to learn than that. The rock I discovered was no ordinary rock. It's size, texture, smoothness, color, and many other observations told me everything I needed to know to find out what kind of rock it was. My rock was a medium sized rock, about three inches long and one inch wide. It is composed of very tiny sediments, almost microscopic, with an arrangement of colors. Its edges are very rigid, and had few bumpy spots on its surface. No signs of layering or banding was evident in the rock sample. The rock is most likely clastic, because it was composed of many fragments and sediments that could be rubbed off easily. The color of the rock is mostly white, with hints of red and black sediments. There are no visible crystals either, but there are a vast amount of grains seen throughout the rock. Mainly due to my observations, I believe that my rock is of a sedimentary origin. I believe this because of several details I made that help justify my classification. First off, the rock's texture is clastic, as there are many visible fragments. I can also tell that the grains in the rock are very fine, due to the fact that I would have to use a microscope to distinguish them. Sediments chip and fall off easily when rubbed against any surface, which proves the sediments and grain size is very small. I narrowed my search down in the Earth Sciences References Tables (ESRT). Looking at the ESRT...
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...Geog 2RC3- Physiographic regions- Jan 10/14 Interior Plains- p.38-39 20 % of Canada’s land mass Sedimentary rocks Low relief Elevation increases from east to west Hudson Bay Lowlands- p- 39-41 3.5 % of landmass Low lying, poorly drained landscape (muskeg) Underlain by sedimentary rocks Arctic Lands- 41-42 Archipelago 10 % of Canada’s landmass Pre-Cambrian crystalline (igneous) rock overlain by Paleozoic sedimentary rock Ellesmere Island Appalachian Uplands- p.42 2% of Canada’s land mass Very old, heavily eroded mountains (Taconic mountains) Geologically complex (sedimentary, igneous, and metamorphic rocks, as a result of 2 periods of orogenesis (440 million years ago to 350 million years ago) Great Lakes-St Lawrence Lowlands- p 42-44 Less than 2% of landmass (1.8%) Smallest- 110 000 sq km 60% of all Canadians live here Underlain by Paleozoic sedimentary rocks Summary Given Canada’s enormous size- considerable variation in physical environment All of Canadian landscape influenced by glaciation Links between physical and human geographies Next- the Niagara Escarpment The Niagara Escarpment Dominant physiographic landform feature in Great Lakes-St Lawrence Lowlands Designated as a UNESCO World Biosphere Reserve in 1990 (12 total in Canada) 1st large scale environmental land use plan in Canada (The Niagara Escarpment Plan) Formation in 2 stages 1. Deposition of sediments by eperic (seas during Ordovician (435-400...
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... Region 3: Rocky Mountain System o Region 4: Pacific Mountain System o Region 5: Atlantic Plain • Review the different regions at: http://tapestry.usgs.gov • Create a 12- to 15-slide PowerPoint® presentation for your selected state or region. • Address the following in your PowerPoint®: o Describe the various geologic events that have occurred in your region. o Describe the geological features and various types of rocks that formed in the area (for example, mountains, craters, canyons, volcanoes, fault lines, or folds). o Choose one of these geological features to research. What is the most prevalent rock type of the feature? Describe the mineral composition of the rock type. o How old is your geologic feature? Estimate the absolute age of the geological feature, and discuss methods used to determine the age. o What geologic event created your chosen geological feature? Discuss the process of plate tectonics related to the formation. o Discuss the significance of igneous, sedimentary, and metamorphic rocks in your region. o Discuss the type(s) of weathering and erosion processes that has most likely affected the physical appearance of your geological feature. o Discuss any significant water, ocean, desert, or glacial feature(s) associated with your region, and the process involved with creating one of them. o Discuss resources that are abundant in the region and the importance and economic value of this resource to the region or...
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...Associate Program Material History of Rock Worksheet Write a 500- to 750-word explanation regarding the role of plate tectonics in the origin of igneous rocks. | ORIGIN OF IGNEOUS ROCKS AND THE ROLE OF PLATE TECTONICS | |Igneous rocks form in three main places: where lithospheric plates pull apart at mid-ocean ridges, where plates come together at | |seduction zones and where continental crust is pushed together, making it thicker and allowing it to heat to melting. There are two| |ideas about igneous rocks that are geologically important. The first idea is that igneous rocks evolve - they change from one kind | |of rock into another. The second idea is that rocks are not randomly distributed across the earth. Specific kinds of rocks are | |always found in specific places for specific reasons, all tied into plate tectonic processes. Igneous rocks begin as hot, fluid | |material, and the word "igneous" comes from the Latin for fire. This material may have been lava erupted at the Earth's surface, or| |magma (un-erupted lava) at shallow depths, or magma in deep bodies (plutons). People commonly think of lava and magma as a liquid, | |like molten metal, but geologists find that magma is usually a mush — a liquid carrying a load of mineral crystals. Magma | |crystallizes into a collection of minerals, and some crystallize sooner than others. Not just that, but when they crystallize...
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...The Rock Cycle is a group of changes. Igneous rock can change into sedimentary rock or into metamorphic rock. Sedimentary rock can change into metamorphic rock or into igneous rock. Metamorphic rock can change into igneous or sedimentary rock.Igneous rock forms when magma cools and makes crystals. Magma is a hot liquid made of melted minerals. The minerals can form crystals when they cool. Igneous rock can form underground, where the magma cools slowly. Or, igneous rock can form above ground, where the magma cools quickly.When it pours out on Earth's surface, magma is called lava. Yes, the same liquid rock matter that you see coming out of volcanoes.On Earth's surface, wind and water can break rock into pieces. They can also carry rock pieces to another place. Usually, the rock pieces, called sediments, drop from the wind or water to make a layer. The layer can be buried under other layers of sediments. After a long time the sediments can be cemented together to make sedimentary rock. In this way, igneous rock can become sedimentary rock.All rock can be heated. But where does the heat come from? Inside Earth there is heat from pressure (push your hands together very hard and feel the heat). There is heat from friction (rub your hands together and feel the heat). There is also heat from radioactive decay (the process that gives us nuclear power plants that make electricity).So, what does the heat do to the rock? It bakes the rock.Baked rock does not melt, but it does change. It...
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...grey intermediate intrusive igneous rock. It occurs in association with either granite or gabbro intrusions. Diorite results from partial melting of mafic rock above a subduction zone. The extrusive equivalent rock type is andesite Diorites in Kenya are found in kakamega dome area, mt. Kenya region, mutito Andei area, matuu-masinga areas in central Kenya and along the Kenyan rift (bogoria region) Quartzite Quartzite is a quartz-rich metamorphic rock, often formed from quartz rich sandstone. The quartz crystals are typically much more tightly interlocked in the quartzite, and the quartzite is more compact, denser, and stronger rock than the original sandstone. Quartzites are found in the Mozambique belt which consists largely of metamorphic rocks. In Kenya they are found to occur mainly in the eastern province that is Kitui county, Machakos county and Mbeere area in Embu Evaporates These are chemical sediments basically formed by chemical processes usually from direct precipitation of solutions They are actually minerals but since they have extensive impurities they are referred to as rocks. Evaporite rocks show ancient conditions of extensive evaporation. Examples of these include; Gypsum deposits (CaSO4.2H2o), anhydrite (CaSO4), and rock salt (Nacl) They occur in Lake Magadi area and Kajiado in Kenya Conglomerate and breccias These are clastic sedimentary rocks formed from the products of the mechanical break up of other rocks. They are coarse grained. Conglomerate...
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...Damantital, Pannatal Lake and Naini Lake. It is spread over an area of 94 sq. km., which marks the catchment of all the seven lakes. Nainital is situated at 29º23’ N latitude, 79º30’ E longitude at an elevation of 2262m (7421ft) above sea level. The climate of the area is typical monsoonal with the three main climatic seasons being rainy (mid-June to mid-September), winter (November to February) and summer (April to mid-June). The transitional periods spring and autumn are March and October respectively. The total mean annual precipitation is around 1100mm/yr and average temperature is 25º C. The vegetation of the region majorly comprises of pine, deodar and evergreen broad leaf species. The primary motive of the field trips was to identify the rock types and various geological features present in the region. The following figure shows a map depicting the sites...
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